Fault-localizer.



E. E. P. CRBIGHTON.

FAULT LOGALIZER. APPLIGATION FILED 11u14, 191s.

Patented Aug. 4, y1914.

TINTTED STATES PATENT OFFICE.

ELMER E. '.F. CREIGHTON, OF SCHENECTADY, NEW' YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION O1" NEW YORK.

FAULT-LOCALIZER.

Specication of Letters Patent.

Application led May 14, 1913.

To all whom it may concern:

lie it known that I, Emma E. F. Camon- 'ro.\', a citizen of the United Stat-es, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Fault-Localizers, of which the following is a specification.

M v invention relates particularly to cable transmission systems and the object of my invention is to localize faults in the cable.

In cable transmission systems it is common practice to inclose the cable in a metallic sheath, often of lead. I propose to divide the metallic sheath into sections, preferably. by inserting insulating material transversely to the length of the cable at more or less equal distances apart, these insulating portions insulating thc sections from cach other. The sheath and cable, as a whole, is insulated from the ground, except that each section of the metallic sheath is supplied with one or more connections to the ground. I provide an indicating means related to cach connection, to indicate the passage of current over4 the respective connections. Now when a fault develops, as by an arc from one of the conductors of the cable, current passes between the conductor and the sheath, and through the connection to that section of the sheath to ground. ln case such a fault develops not only will that connection carry current which is attached to the section of the sheath to which the arc forms, but every other connection to every other section will carry charging current to their respective sections. However, the connection to the faulty section will of necessity carry a current equal to the sum of all the currents carried by the other connections and this condition makes it possible to pick out the faulty section. This differentiation may be obtained by setting the indicators to operate at a certain minimum value, which value is greater than the value of the charging current of a. section. Only the connection to the faulty section carries a current sufficient to operate an indicating means and hence the indicating means relating to the. faulty section is the only indicating means operated. I pre` fer, however, to combine all or a plurality of the indicating means in such a way that the greater strength of the current on the connection to the faulty cable prevents the operation of the indicating means related to the other connections.

My invention will be better understood from the specific construction subsequently described. i

In the accompanying drawings which form a part of my specification the single figure illustrates a part of a cable svstem of distribution involving my invention.

rlhe sections of the metallic sheath of a part of the cable of the system are illustratcd at lO, 11, 1Q and 13, these sections being insulated from cach other by the insulating bodies 1J: transverse to the extension of the cable. Connecting the respective sections of the sheath to form a conducting path to ground are connections 15, 16, 17 and 18. In each of the connections I have provided a transformer 19, the secondary of which supplies energy to the respective indicator. The indicators may assume a variety of forms, for example, at 21 is shown one form of indicator. The solenoid 25 of this indicator is connected to the secondary of the respective transformer 19. The core 26 of this solenoid carries a hook member 27, normally out of engagement with the ring 22. The ring Q2 is movable vertically and is guided by the arm 23 sliding in h fixed member 24, and the ring 22 is normally held in the position illustrated by the spring 2S. A battery 29 is connected to the arm .23 at one sifle and at the other side through the bell or other signal 20 to the hook member Q7. Now in case a fault develops in the section of the sheath of the cable, current Hows to or from the ground over the connection 15, and hence through the respective transformer 1f). The solenoid 25 is energized and providing the strength over the connection is suflicient, the -core 2G is pulled into the solenoid and contact is made between the hook member 27 and the ring 22. A circuit is thus completed through the battery 29 and the indicator 2O showing that the section 10 is faulty. Now, as before pointed out, if cach section of the cable is provided with such an indicating means or with similar indicating means, for example such as is shown at the right of the figure and later described, all the indicaters tend to operate on the development et a fault, unless special provisions are made. Such provisions may consist in requiring that the cores be drawn into the respective solenoids only when the current iu the solfnoid exceeds a certain minimum value. This value. may be such that it is reached only when the fault develops in the .section to which the respective connection is made. the charging currents to the healthy sections being below the minimum value retpiired to operate. the inz'licators. I prefer. howevert to combine or interlock the indicators` in .such a way that the indicator responding to the greatest current, prevents the operation ot' other indicators. Such a combination ot' indicating means I have shown at 30. The respective transformers 19 in the. connections lo and 1T supply the solonoids 35 and 3G. These soleuoids contrcl the cores 37 and 38 which carry the hook members 39 and 40 respectively. The cores are also connected in thisl case through their hook members 39 and l0 to the springs l1 and 4Q respectively, the other ends of the. springs being held stationary. A ring El provided with a guiding arm 32 sliding in a stationary member and normally held in one position by the spring 34, is adapted to be acted upon by both hook meinbers 8i) and 40.

A signal means 2O is provided for each hook member 39, and lO, the circuit through the signal means being completed by the engagement of the respective hook member with the ring 31. as pointed out with refcrence to the indicator Q1. Assuming that an are forms between one of the conductors of the cable and the section l2 of the sheath Current is carried by the connection 1T and also by every other connection to every other section of the sheath of the cable. The current in the connection 1T is however approximately equal to the sum of the currents in all the other connections. rl`he result is that the solenoid 3G is more highly energized than the solenoid 35 and the core 88 is pulled farther into the solenoid 3V against the tension of its spring 42, than is the core 3T into its solenoid 35 against the tension of its spring 4l. The hoolt member 40, therefore, picks up the ring 31 and pulls it against the tension of its spring 34 beyond the reach of the hook member 3S). The circuit is thus completed through the respective signal member Q0 connected to the hook member 40, but is uncomplcted through the signal means 20 connected to the hook member 39. If desired this particular differentiating indicating means may be combined with a means of a type similar to 21 first described: Thus at 50 have shown an indicator including a solenoid 51 controlling the core 52 operating in its turn the lever 53. This controls the cirl cuit through the wires 54 and the respective signaling means 20. lt is necessary as before pointed out to provide that the core 52 shall be drawn into its solenoid 5l only when that solenoid carriesl a current of at least a definite minimum value. \\'hcn such an indicating meansl is combined with an indicating means similar to ZBO, it is also necessary that the solenoids and 3G pich up their cores only when carrying currents of at least the same minimum value. lf desired, a number ot' the signaling means 2O may be assembled at one station by using pilot wires, as shown in one instance at 54. For the purpose oi changing the character of, or controlling, thc current on the connections, it may1 in some instances be desirable to insert resistance GO in the connections.

vWhat, I claim as new and desire to secure by Letters Patent, of the United States, is:

l. The combination with a system ot distribution including a cable carrying conductors and havingl a metallic sheath divided into sections insulated from each other` ol a connection between a section of the sheath and ground and means for indicating the passage of current over said connection.

2. The combination with a system ot' distribution including a cable carrying conductors and having a metallic sheath divided into sections` insulated from each other, of a connection betwen cach section of the sheath and ground and means related to each connection for indicating the passage of current over the respective connections.

3. The combination with a system of distribution including a cable carrying conductors and having a metallic sheath divided into sections insulated from each other, of a connection between each section of the sheath and ground and means related to each connection for indicating the connection carrying the greatest current.V

il. The combination with a system of distribution including a cable carrying conductors 'and having a metallic sheath divided into sections insulated from each other transversely to the extension of the cable, of a connection between cach section and ground and means related to cach connection for indicating the connection carryingr the greatest current.

ln combination with a cable having a plurality of conductors. a metallic sheath surrounding said cable divided into sections, said sections being insulated from xach other, of a conducting path from each of said sections to ground, and means operatively related to each conducting path for indicating the passage of current in said path.

(t. Tn combination with a cable havino a plurality of conductors. n metallic sheiith surrounding said cable divided into sections which are insulated from each other, and a connection to ground from each of sadsecn Witness Wha-eef, have hereunto set tons, of an deleetroresponsive device opemmyhand this 12th day of May, 1913.

tive y relate o each of said sections for n- -w L v, n 1 T Tv dcatng the connection having the greatest IMJ'MER E' E' (JRElGdTOk 5 current How whereby a fault between said Ttnessest eonductors and any of said sections is selee- HELEN QRFORD,

.tively determined. v v BENJAMIN B. HULL. 

